So says Politico, based on “dozens” of interviews with formerly pro-Obama Jewish voters and donors conducted by Ben Smith since Barack Obama’s May speech in which he demanded a return to 1967 lines for Israel, “with swaps,” as the basis of a peace plan.  That speech more than anything else has Obama’s supporters wondering whether they made a mistake in 2008, and some of them may even do the unthinkable — vote Republican:

If several dozen interviews with POLITICO are any indication, a similar conversation is taking place in Jewish communities across the country. Obama’s speech last month seems to have crystallized the doubts many pro-Israel Democrats had about Obama in 2008 in a way that could, on the margins, cost the president votes and money in 2012 and will not be easy to repair.

“It’s less something specific than that these incidents keep on coming,” said Ainsman.

The immediate controversy sparked by the speech was Obama’s statement that Israel should embrace the country’s 1967 borders, with “land swaps,” as a basis for peace talks. Prime Minister Benjamin Netanyahu seized on the first half of that phrase and the threat of a return to what Israelis sometimes refer to as “Auschwitz borders.”

Obama’s Jewish allies stressed the second half: that land swaps would — as American negotiators have long contemplated — give Israel security in its narrow middle, and the deal would give the country international legitimacy and normalcy.

But the noisy fray after the speech mirrored any number of smaller controversies. Politically hawkish Jews and groups such as the Republican Jewish Coalition and the Emergency Committee for Israel pounded Obama in news releases. White House surrogates and staffers defended him, as did the plentiful American Jews who have long wanted the White House to lean harder on Israel’s conservative government.

Based on the conversations with POLITICO, it’s hard to resist the conclusion that some kind of tipping point has been reached.

Republicans should hold off on celebrating just yet.  Jewish voters are one of the bedrock demographics for the Democratic Party, almost as loyal as black voters.  In 2008, Obama got 78% of the Jewish vote despite the questions raised by his association with Hamas-supporting Jeremiah Wright at Trinity United, as well as a campaign adviser’s connections to Hamas. They still supported him despite having Samantha Power on his campaign team and in his administration (as a Special Adviser to the President for Multilateral Affairs, no less), a woman who once proposed that Western nations occupy Israel to disarm the IDF in order to impose peace in the region.

Honestly, if that list of clues didn’t convince Jewish voters of Obama’s lack of sympathy for Israel, it’s hard to imagine that a reference to 1967 lines would provide the necessary Technicolor moment.

The Jewish vote won’t suddenly swing to the GOP, for reasons that have nothing to do with Obama.  Jewish voters tend to be more progressive; the Democratic Party is a more natural home for them.  While there may be some truth in the notion that African-Americans are naturally more conservative and could be won over with a more concerted effort by Republicans to address their issues through debate (as Jack Kemp tried), that’s almost certainly not true of Jewish voters as a bloc.  The GOP position on Israel might be a better fit, but on domestic politics, they’ll keep voting Democratic.

But they may not be as willing to donate, especially to Obama, and that may be all it takes in what is already shaping up as a tough re-election campaign:

Others involved in the Philadelphia event, however, said they think Jewish doubts are taking a fundraising toll.

“We’re going to raise a ton of money, but I don’t know if we’re going to hit our goals,” said Daniel Berger, a lawyer who is firmly in the “peace camp” and said he blamed the controversy on Netanyahu’s intransigence.

I’d suspect that the effect will be more subtle, as it will be on the hard Left.  Republicans probably won’t make significant inroads with these voters, and exit polls in 2012 will likely show similar breakdowns as 2008.  The difference will be fewer voters coming to the polls to support Obama as others sit on their hands … and their cash.